Osteoarthritis

Background

Osteoarthritis is the most common type of joint disease, affecting more than 20 million

individuals in the United States alone (see Epidemiology). It represents a heterogeneous group of

conditions resulting in common histopathologic and radiologic changes. It can be thought of as a

degenerative disorder arising from biochemical breakdown of articular (hyaline) cartilage in the

synovial joints. However, the current view holds that osteoarthritis involves not only the articular

cartilage but also the entire joint organ, including the subchondral bone and synovium.

Osteoarthritis predominantly involves the weight-bearing joints, including the knees, hips,

cervical and lumbosacral spine, and feet. Other commonly affected joints include the distal

interphalangeal (DIP), proximal interphalangeal (PIP), and carpometacarpal (CMC) joints. This

article primarily focuses on osteoarthritis of the hand, knee, and hip joints (see Pathophysiology).

For more information on arthritis in other joints, see Glenohumeral Arthritis and Wrist Arthritis.

Although osteoarthritis was previously thought to be caused largely by excessive wear and tear,

increasing evidence points to the contributions of abnormal mechanics and inflammation.

Therefore, the term degenerative joint disease is no longer appropriate in referring to

osteoarthritis. (See Pathophysiology.)

Historically, osteoarthritis has been divided into primary and secondary forms, though this

division is somewhat artificial. Secondary osteoarthritis is conceptually easier to understand: It

refers to disease of the synovial joints that results from some predisposing condition that has

adversely altered the joint tissues (eg, trauma to articular cartilage or subchondral bone).

Secondary osteoarthritis can occur in relatively young individuals (see Etiology). [1, 2, 3, 4, 5, 6, 7, 8, 9, 10,

11]

The definition of primary osteoarthritis is more nebulous. Although this form of osteoarthritis is

related to the aging process and typically occurs in older individuals, it is, in the broadest sense

of the term, an idiopathic phenomenon, occurring in previously intact joints and having no

apparent initiating factor.

Some clinicians limit the term primary osteoarthritis to the joints of the hands (specifically, the

DIP and PIP joints and the joints at the base of the thumb). Others include the knees, hips, and

spine (apophyseal articulations) as well.

As underlying causes of osteoarthritis are discovered, the term primary, or idiopathic,

osteoarthritis may become obsolete. For instance, many investigators believe that most cases of

primary osteoarthritis of the hip may, in fact, be due to subtle or even unrecognizable congenital

or developmental defects.

No specific laboratory abnormalities are associated with osteoarthritis. Rather, it is typically

diagnosed on the basis of clinical findings, with or without radiographic studies (see Workup).

The goals of osteoarthritis treatment include pain alleviation and improvement of functional

status. Nonpharmacologic interventions are the cornerstones of osteoarthritis therapy and include

the following:

Patient education

Application of heat and cold

Weight loss

Exercise

Physical therapy

Occupational therapy

Joint unloading, in certain joints (eg, knee and hip)

Intra-articular pharmacologic therapy includes corticosteroid injection and viscosupplementation,

which may provide pain relief and have an anti-inflammatory effect on the affected joint. (See

Treatment.) Oral pharmacologic therapy begins with acetaminophen for mild or moderate pain

without apparent inflammation.

If the clinical response to acetaminophen is not satisfactory or the clinical presentation is

inflammatory, consider nonsteroidal anti-inflammatory drugs (NSAIDs). (See Medication.) If all

other modalities are ineffective and osteotomy is not viable, or if a patient cannot perform his or

her daily activities despite maximal therapy, arthroplasty is indicated.

The high prevalence of osteoarthritis entails significant costs to society. Direct costs include

clinician visits, medications, and surgical intervention. Indirect costs include such items as time

lost from work.

Costs associated with osteoarthritis can be particularly significant for elderly persons, who face

potential loss of independence and who may need help with daily living activities. As the

populations of developed nations age over the coming decades, the need for better understanding

of osteoarthritis and for improved therapeutic alternatives will continue to grow. (See

Epidemiology.)

Anatomy

Joints can be classified in either functional or structural terms. A functional classification, based

on movement, would categorize joints as follows:

Synarthroses (immovable)

Amphiarthroses (slightly moveable)

Diarthroses (freely moveable)

A structural classification would categorize joints as follows:

Synovial

Fibrous

Cartilaginous

Normal synovial joints allow a significant amount of motion along their extremely smooth

articular surface. These joints are composed of the following:

Articular cartilage

Subchondral bone

Synovial membrane

Synovial fluid

Joint capsule

The normal articular surface of synovial joints consists of articular cartilage (composed of

chondrocytes) surrounded by an extracellular matrix that includes various macromolecules, most

importantly proteoglycans and collagen. The cartilage facilitates joint function and protects the

underlying subchondral bone by distributing large loads, maintaining low contact stresses, and

reducing friction at the joint.

Synovial fluid is formed through a serum ultrafiltration process by cells that form the synovial

membrane (synoviocytes). Synovial cells also manufacture hyaluronic acid (HA, also known as

hyaluronate), a glycosaminoglycan that is the major noncellular component of synovial fluid.

Synovial fluid supplies nutrients to the avascular articular cartilage; it also provides the viscosity

needed to absorb shock from slow movements, as well as the elasticity required to absorb shock

from rapid movements.

Pathophysiology

Primary and secondary osteoarthritis are not separable on a pathologic basis, though bilateral

symmetry is often seen in cases of primary osteoarthritis, particularly when the hands are

affected.[12, 13] Traditionally, osteoarthritis was thought to affect primarily the articular cartilage of

synovial joints; however, pathophysiologic changes are also known to occur in the synovial

fluid, as well as in the underlying (subchondral) bone, the overlying joint capsule, and other joint

tissues (see Workup).[14, 15, 16, 17]

Although osteoarthritis has been classified as a noninflammatory arthritis, increasing evidence

has shown that inflammation occurs as cytokines and metalloproteinases are released into the

joint. These agents are involved in the excessive matrix degradation that characterizes cartilage

degeneration in osteoarthritis.[18] Therefore, it is no longer appropriate to use the term

degenerative joint disease when referring to osteoarthritis.

In early osteoarthritis, swelling of the cartilage usually occurs, because of the increased synthesis

of proteoglycans; this reflects an effort by the chondrocytes to repair cartilage damage. This

stage may last for years or decades and is characterized by hypertrophic repair of the articular

cartilage.

As osteoarthritis progresses, however, the level of proteoglycans eventually drops very low,

causing the cartilage to soften and lose elasticity and thereby further compromising joint surface

integrity. Microscopically, flaking and fibrillations (vertical clefts) develop along the normally

smooth articular cartilage on the surface of an osteoarthritic joint. Over time, the loss of cartilage

results in loss of joint space.

In major weight-bearing joints of persons with osteoarthritis, a greater loss of joint space occurs

at those areas experiencing the highest loads. This effect contrasts with that of inflammatory

arthritides, in which uniform joint-space narrowing is the rule.

In the osteoarthritic knee, for example, the greatest loss of joint space is commonly seen in the

medial femorotibial compartment, though the lateral femorotibial compartment and

patellofemoral compartment may also be affected. Collapse of the medial or lateral

compartments may result in varus or valgus deformities, respectively.

Erosion of the damaged cartilage in an osteoarthritic joint progresses until the underlying bone is

exposed. Bone denuded of its protective cartilage continues to articulate with the opposing

surface. Eventually, the increasing stresses exceed the biomechanical yield strength of the bone.

The subchondral bone responds with vascular invasion and increased cellularity, becoming

thickened and dense (a process known as eburnation) at areas of pressure.[19]

The traumatized subchondral bone may also undergo cystic degeneration, which is attributable

either to osseous necrosis secondary to chronic impaction or to the intrusion of synovial fluid.

Osteoarthritic cysts are also referred to as subchondral cysts, pseudocysts, or geodes (the

preferred European term) and may range from 2 to 20 mm in diameter. Osteoarthritic cysts in the

acetabulum (see the image below) are termed Egger cysts.

This radiograph demonstrates osteoarthritis of the right hip,

including the finding of sclerosis at the superior aspect of the acetabulum. Frequently,

osteoarthritis at the hip is a bilateral finding, but it may occur unilaterally in an individual who

has a previous history of hip trauma that was confined to that one side.

At areas along the articular margin, vascularization of subchondral marrow, osseous metaplasia

of synovial connective tissue, and ossifying cartilaginous protrusions lead to irregular outgrowth

of new bone (osteophytes). Fragmentation of these osteophytes or of the articular cartilage itself

results in the presence of intra-articular loose bodies (joint mice).

Along with joint damage, osteoarthritis may also lead to pathophysiologic changes in associated

ligaments and the neuromuscular apparatus. For example, lateral collateral ligament complex

abnormalities are common in knee osteoarthritis.

Pain mechanisms in osteoarthritis

Pain, the main presenting symptom of osteoarthritis, is presumed to arise from a combination of

mechanisms, including the following:

Osteophytic periosteal elevation

Vascular congestion of subchondral bone, leading to increased intraosseous pressure

Synovitis with activation of synovial membrane nociceptors

Fatigue in muscles that cross the joint

Overall joint contracture

Joint effusion and stretching of the joint capsule

Torn menisci

Inflammation of periarticular bursae

Periarticular muscle spasm

Psychological factors

Crepitus (a rough or crunchy sensation)

Central pain sensitization

When the spine is involved in osteoarthritis, especially the lumbar spine, the associated changes

are very commonly seen from L3 through L5. Symptoms include pain, stiffness, and occasional

radicular pain from spinal stenosis. Foraminal narrowing is caused by facet arthritic changes that

result in compression of the nerve roots. Acquired spondylolisthesis is a common complication

of arthritis of the lumbar spine.

Etiology

The daily stresses applied to the joints, especially the weight-bearing joints (eg, ankle, knee, and

hip), play an important role in the development of osteoarthritis. Most investigators believe that

degenerative alterations in osteoarthritis primarily begin in the articular cartilage, as a result of

either excessive loading of a healthy joint or relatively normal loading of a previously disturbed

joint. External forces accelerate the catabolic effects of the chondrocytes and further disrupt the

cartilaginous matrix.[20, 21, 22, 23]

Risk factors for osteoarthritis include the following[24, 25, 26, 27] :

Age

Obesity[28, 29, 30]

Trauma

Genetics (significant family history)

Reduced levels of sex hormones

Muscle weakness[31]

Repetitive use (ie, jobs requiring heavy labor and bending)[32]

Infection

Crystal deposition

Acromegaly

Previous inflammatory arthritis (eg, burnt-out rheumatoid arthritis)

Heritable metabolic causes (eg, alkaptonuria, hemochromatosis, and Wilson disease)

Hemoglobinopathies (eg, sickle cell disease and thalassemia)

Neuropathic disorders leading to a Charcot joint (eg, syringomyelia, tabes dorsalis, and

diabetes)

Underlying morphologic risk factors (eg, congenital hip dislocation and slipped femoral capital

epiphysis)

Disorders of bone (eg, Paget disease and avascular necrosis)

Previous surgical procedures (eg, meniscectomy)

Advancing age

With advancing age come reductions in cartilage volume, proteoglycan content, cartilage

vascularization, and cartilage perfusion. These changes may result in certain characteristic

radiologic features, including a narrowed joint space and marginal osteophytes. However,

biochemical and pathophysiologic findings support the notion that age alone is an insufficient

cause of osteoarthritis.

Obesity

Obesity increases the mechanical stress in a weight-bearing joint. It has been strongly linked to

osteoarthritis of the knees and, to a lesser extent, of the hips. A study that evaluated the

associations between body mass index (BMI) over 14 years and knee pain at year 15 in 594

women found that a higher BMI at year 1 and a significant increase in BMI over 15 years were

predictors of bilateral knee pain at year 15.[30] The association between BMI increase and knee

pain was independent of radiographic changes.

In addition to its mechanical effects, obesity may be an inflammatory risk factor for

osteoarthritis. Obesity is associated with increased levels (both systemic and intra-articular) of

adipokines (cytokines derived from adipose tissue), which may promote chronic, low-grade

inflammation in joints.[33]

Other causes

Trauma or surgery (including surgical repair of traumatic injury) involving the articular cartilage,

ligaments, or menisci can lead to abnormal biomechanics in the joints and accelerate

osteoarthritis. Although repairs of ligament and meniscal injuries usually restore joint function,

osteoarthritis has been observed 5-15 years afterward in 50-60% of patients.[34]

Insults to the joints may occur even in the absence of obvious trauma. Microtrauma may also

cause damage, especially in individuals whose occupation or lifestyle involves frequent

squatting, stair-climbing, or kneeling.

Muscle dysfunction compromises the body’s neuromuscular protective mechanisms, leading to

increased joint motion and ultimately resulting in osteoarthritis. This effect underscores the need

for continued muscle toning exercises as a means of preventing muscle dysfunction.

Genetics

A hereditary component, particularly in osteoarthritis presentations involving multiple joints, has

long been recognized.[35, 36, 37] Several genes have been directly associated with osteoarthritis,[38] and many more have been determined to be associated with contributing factors, such as

excessive inflammation and obesity.

Genes in the BMP (bone morphogenetic protein) and WNT (wingless-type) signaling cascades

have been implicated in osteoarthritis. Two genes in particular,GDF5 (growth and differentiation

factor 5) and FRZB (frizzled related protein) have been identified in the articular cartilage in

animal studies and share a strong correlation with osteoarthritis.[39, 40, 41, 42]

Genome-wide association studies (GWAS) have identified an association between osteoarthritis

of large joints and the MCF2L gene. This gene is key in neurotrophin-mediated regulation of

peripheral nervous system cell motility.[43]

Genetic factors are also important in certain heritable developmental defects and skeletal

anomalies that can cause congenital misalignment of joints. These may result in damage to

cartilage and the structure of the joint.

Currently, clinical genetic testing is not offered to patients who have osteoarthritis unless they

also have other anomalies that could be associated with a genetic condition. In the future, testing

may allow individualization of therapeutics.

Epidemiology

United States and international statistics

Osteoarthritis affects more than 20 million individuals in the United States, though statistical

figures are influenced by how the condition is defined—that is, by self-report, by radiographic or

symptomatic criteria, or by a combination of these.[44]On the basis of the radiographic criteria for

osteoarthritis, more 50% of adults older than 65 years are affected by the disease.

Internationally, osteoarthritis is the most common articular disease. Estimates of its frequency

vary across different populations.

Age-related demographics

Primary osteoarthritis is a common disorder of the elderly, and patients are often asymptomatic.

Approximately 80-90% of individuals older than 65 years have evidence of radiographic primary

osteoarthritis.[45]

Symptoms typically do not become noticeable until after the age of 50 years. The prevalence of

the disease increases dramatically among persons older than 50 years, likely because of age-

related alterations in collagen and proteoglycans that decrease the tensile strength of the joint

cartilage and because of a diminished nutrient supply to the cartilage.[45]

Sex-related demographics

In individuals older than 55 years, the prevalence of osteoarthritis is higher among women than

among men.[45] Women are especially susceptible to osteoarthritis in the DIP joints of the fingers.

Women also have osteoarthritis of the knee joints more frequently than men do, with a female-

to-male incidence ratio of 1.7:1. Women are also more prone to erosive osteoarthritis, with a

female-to-male ratio of about 12:1.

Race-related demographics

Interethnic differences in the prevalence of osteoarthritis have been noted.[46] The disorder is

more prevalent in Native Americans than in the general population. Disease of the hip is seen

less frequently in Chinese patients from Hong Kong than in age-matched white populations.

Symptomatic knee osteoarthritis is extremely common in China.[47]

In persons older than 65 years, osteoarthritis is more common in whites than in blacks. Knee

osteoarthritis appears to be more common in black women than in other groups. Jordan et al

found that in comparison with whites, African American men and women had a slightly higher

prevalence of radiographic and symptomatic knee osteoarthritis but a significantly higher

prevalence of severe radiographic knee osteoarthritis.[48]

Prognosis

The prognosis in patients with osteoarthritis depends on the joints involved and on the severity of

the condition. No proven disease- or structure-modifying drugs for osteoarthritis are currently

known; consequently, pharmacologic treatment is directed at symptom relief.

A systematic review found the following clinical features to be associated with more rapid

progression of knee osteoarthritis[49] :

Older age

Higher BMI

Varus deformity

Multiple involved joints

Patients with osteoarthritis who have undergone joint replacement have a good prognosis, with

success rates for hip and knee arthroplasty generally exceeding 90%. However, a joint prosthesis

may have to be revised 10-15 years after its placement, depending on the patient’s activity level.

Younger and more active patients are more likely to require revisions, whereas the majority of

older patients will not. (See Treatment.)

Patient Education

Educate patients on the natural history of and management options for osteoarthritis,

emphasizing the benefits of exercise and weight loss. Explain the differences between

osteoarthritis and more rapidly progressive arthritides, such as rheumatoid arthritis.

Several Arthritis Foundation studies have demonstrated that education in osteoarthritis benefits

the patient. Through education, patients can learn and implement strategies for reducing pain and

improving joint function. Emphasize the need for physician follow-up visits.

For patient education information, see the Arthritis Center, as well asOsteoarthritis.

Approach Considerations

The goals of osteoarthritis treatment include alleviation of pain and improvement of functional

status.[61] Optimally, patients should receive a combination of nonpharmacologic and

pharmacologic treatment.[62]

Nonpharmacologic interventions, which are the cornerstones of osteoarthritis therapy, include

the following:

Patient education

Heat and cold

Weight loss[63]

Exercise

Physical therapy

Occupational therapy

Unloading in certain joints (eg, knee, hip)

A physiatrist may help in formulating a nonpharmacologic management plan for the patient with

osteoarthritis, and a nutritionist may help the patient to lose weight. A referral to an orthopedic

surgeon may be necessary if the osteoarthritis fails to respond to a medical management plan.

Surgical procedures for osteoarthritis include arthroscopy, osteotomy, and (particularly with knee

or hip osteoarthritis) arthroplasty.

Pharmacologic Treatment

American College of Rheumatology guidelines

The American College of Rheumatology (ACR) has issued guidelines for pharmacologic

treatment of osteoarthritis of the hand, hip, and knee.( [48] For hand osteoarthritis, the ACR

conditionally recommends using 1 or more of the following:

Topical capsaicin

Topical nonsteroidal anti-inflammatory drugs (NSAIDs), including trolamine salicylate

Oral NSAIDs

Tramadol

The ACR conditionally recommends against using intra-articular therapies or opioid analgesics

for hand osteoarthritis. For patients 75 years and older, the ACR conditionally recommends the

use of topical rather than oral NSAIDs.

For knee osteoarthritis, the ACR conditionally recommends using 1 of the following:

Acetaminophen

Oral NSAIDs

Topical NSAIDs

Tramadol

Intra-articular corticosteroid injections

The ACR conditionally recommends against using chondroitin sulfate, glucosamine, or topical

capsaicin for knee osteoarthritis. The ACR has no recommendations regarding the use of intra-

articular hyaluronates, duloxetine, and opioid analgesics.

For hip osteoarthritis, the ACR conditionally recommends using 1 or more of the following for

initial management:

Acetaminophen

Oral NSAIDs

Tramadol

Intra-articular corticosteroid injections

The ACR conditionally recommends against using chondroitin sulfate or glucosamine for hip

osteoarthritis. The ACR has no recommendation regarding the use of topical NSAIDs, intra-

articular hyaluronate injections, duloxetine, or opioid analgesics.

Agency for Healthcare Research and Quality findings

A comparison of analgesics for osteoarthritis carried out by the Agency for Healthcare Research

and Quality (AHRQ) found that “no currently available analgesic reviewed in this report offers a

clear overall advantage compared with the others.”[64] The choice of analgesic for an individual

patient should take into account the trade-off between benefits and adverse effects, which differs

across analgesics. Patient age, comorbid conditions, and concomitant medication are key

considerations.

The AHRQ comparison found that acetaminophen was modestly inferior to NSAIDs in reducing

osteoarthritic pain but was associated with a lower risk of GI adverse effects. [64] On the other

hand, acetaminophen poses a higher risk of liver injury.

AHRQ findings on adverse effects included the following:

Selective NSAIDs as a class were associated with a lower risk of ulcer complications than

were the nonselective NSAIDs naproxen, ibuprofen, and diclofenac

The partially selective NSAIDs meloxicam and etodolac were associated with a lower risk of

ulcer-related complications and symptomatic ulcers than were various nonselective NSAIDs

The risk of serious GI adverse effects was found to be higher with naproxen than with

ibuprofen

Celecoxib and the nonselective NSAIDs ibuprofen and diclofenac were associated with an

increased risk of cardiovascular adverse effects when compared with placebo

The nonselective NSAIDs ibuprofen and diclofenac, but not naproxen, were associated with an

increased risk of heart attack when compared with placebo

The AHRQ noted that topical diclofenac was found to have efficacy similar to that of oral

NSAIDs in patients with localized osteoarthritis. No head-to-head trials compared topical

salicylates or capsaicin with oral NSAIDs for osteoarthritis.[64]

All NSAIDs had deleterious effects on blood pressure, edema, and kidney function. However,

the AHRQ found no consistent clinically relevant differences between celecoxib, partially

selective NSAIDs, and nonselective NSAIDs with regard to the risk of hypertension, heart

failure, or impaired kidney function.[64]

Analgesics, NSAIDs, and COX-2 inhibitors

Begin treatment with acetaminophen for mild or moderate osteoarthritic pain without apparent

inflammation. If the clinical response to acetaminophen is not satisfactory or if the clinical

presentation of osteoarthritis is inflammatory, consider using an NSAID.

Use the lowest effective dose or intermittent dosing if symptoms are intermittent, then try full

doses if the patient’s response is insufficient.

Topical NSAID preparations, particularly diclofenac, are available. These preparations can be

particularly useful in patients with symptomatic disease that is limited to a few sites or in patients

who are at increased risk for adverse events with systemic NSAIDs.

In patients with highly resistant pain, consider the analgesic tramadol. Options in patients at an

elevated risk for GI toxicity from NSAIDs include the addition of a proton-pump inhibitor or

misoprostol to the treatment regimen and the use of the selective cyclooxygenase (COX)-2

inhibitor celecoxib instead of a nonselective NSAID.

Duloxetine

The selective serotonin-norepinephrine reuptake inhibitor duloxetine has been found to be

effective in treating osteoarthritis pain.[65] For example, in patients with knee osteoarthritis who

had persistent moderate pain despite optimized NSAID therapy, a randomized, double-blind trial

found significant additional pain reduction and functional improvement with duloxetine as

compared with placebo.[66]

However, duloxetine was also associated with significantly more nausea, dry mouth,

constipation, fatigue, and decreased appetite than placebo was.[66] To date, trials of duloxetine in

osteoarthritis have been short in duration (10-13 weeks), and studies comparing duloxetine

directly with other therapies have not been performed.

Intra-articular injections

Intra-articular pharmacologic therapy includes injection of a corticosteroid or sodium

hyaluronate (ie, hyaluronic acid [HA] or hyaluronan), which may provide pain relief and have an

anti-inflammatory effect on the affected joint.[67, 68]Ultrasound guidance can facilitate

arthrocentesis and injection and is increasingly being adopted by physicians such as

rheumatologists and physiatrists for this purpose.

Corticosteroid

After the introduction of the needle into the joint and before steroid administration, aspiration of

as much synovial fluid as possible should be attempted. Aspiration often provides symptomatic

relief for the patient and allows laboratory evaluation of the fluid, if necessary. Infected joint

fluid and bacteremia are contraindications to steroid injection.

In patients with osteoarthritic knee pain, steroid injections generally result in clinically and

statistically significant pain reduction as soon as 1 week after injection. The effect may last, on

average, anywhere from 4 to 6 weeks per injection, but the benefit is unlikely to continue beyond

that time frame.[69] For hip osteoarthritis, a randomized, placebo-controlled study confirmed the

effectiveness of corticosteroid injection, with benefits often lasting as long as 3 months.[70]

Some controversial evidence exists regarding frequent steroid injections and subsequent damage

to cartilage (chondrodegeneration). Accordingly, it is usually recommended that no more than 3

injections per year be delivered to any individual osteoarthritic joint. Systemic glucocorticoids

have no role in the management of osteoarthritis.

For more information, see Corticosteroid Injections of Joints and Soft Tissues.

Sodium hyaluronate

Intra-articular injection of sodium hyaluronate, also referred to as viscosupplementation, has

been shown to be safe and possibly effective for symptomatic relief of knee osteoarthritis. [71, 72] In

the United States, intra-articular HAs are classified as medical devices rather than as drugs.[73]

Intra-articular HAs approved by the FDA for the treatment of osteoarthritic knee pain include the

naturally extracted, non–cross-linked sodium hyaluronate products Hyalgan,[74] Supartz,

Orthovisc, and Euflexxa, as well as the cross-linked sodium hyaluronate product known as hylan

G-F 20 (Synvisc).

Euflexxa is derived from a fermentation process (Streptococcus), whereas the source material for

the other products listed is chicken combs. At present, no distinct advantage or disadvantage has

been associated with any particular source of HA.

Some differences between the viscosupplements do exist in the FDA-approved prescribing

information. For example, whereas Hyalgan and Synvisc have been established as safe for repeat

treatment, the safety and efficacy of other products for repeat treatment have not been

established.

The exact mechanisms of action through which HAs provide symptomatic relief are unknown.

Possible mechanisms include direct binding to receptors (CD44 in particular) in the synovium

and cartilage that can lead to several biologic activation pathways.[75, 76]

The HA class in general has demonstrated a very favorable safety profile for chronic pain

management in knee osteoarthritis, with the most common adverse event being injection-site

pain. Although any intra-articular injection (whether of HAs or of steroids) may elicit an

inflammatory response and possible effusion, only the cross-linked hylan G-F 20 product has

been associated with a clinically distinct acute inflammatory side effect (ie, severe acute

inflammatory reaction [SAIR] or HA-associated intra-articular pseudosepsis).

Additional pharmacologic agents

Muscle relaxants may benefit patients with evidence of muscle spasm. Judicious use of narcotics

(eg, oxycodone and acetaminophen with codeine) is reserved for patients with severe

osteoarthritis.

Glucosamine and chondroitin sulfate have been used in Europe for many years and continue to

be popular with patients worldwide. In the United States, however, the glucosamine/chondroitin

arthritis intervention trial (GAIT) reported, at best, limited benefit from glucosamine (500 mg 3

times daily), chondroitin sulfate (400 mg 3 times daily), or the combination of the 2 in patients

with knee osteoarthritis.[77, 78]

In GAIT patients overall, glucosamine and chondroitin sulfate alone or in combination did not

reduce pain effectively at 24 weeks, but in patients with moderate-to-severe pain at baseline, the

rate of response was significantly higher with combined therapy than with placebo (79.2% vs.

54.3%).[78] At 2 years, no treatment achieved a clinically important difference in loss of joint-

space width, though treatment effects on Kellgren-Lawrence grade 2 knees showed a trend

toward improvement relative to the placebo group.[77]

The AHRQ comparison found no clear difference between glucosamine or chondroitin and oral

NSAIDs for relieving pain or improving function.[64] However, the AHRQ observed that most

trials showing therapeutic benefits from glucosamine used pharmaceutical-grade glucosamine

that is not available in the United States, noting that the trial findings may therefore be

inapplicable to currently available over-the-counter preparations.

Another agent, S-adenosylmethionine (SAM-e), is a European supplement receiving significant

attention in the United States. A systematic review of SAM-e found that the evidence was

inconclusive, with a number of small trials of questionable quality; the authors concluded that

the effects of SAM-e on pain and function may be potentially clinically relevant but are expected

to be small.[79]

Chondroprotective drugs (ie, matrix metalloproteinase [MMP] inhibitors and growth factors) are

being tested as disease-modifying drugs in the management of osteoarthritis. For example,

MMP-13 is specifically expressed in the cartilage of individuals with osteoarthritis but not in the

cartilage of normal adults.[80] German researchers reported on the synthesis and biologic

evaluation of an MMP-13 selective inhibitor that has demonstrated efficacy as a disease-

modifying intra-articular injection for osteoarthritis.[81]

Other investigational agents include monoclonal antibodies that inhibit nerve growth factor

(NGF), such as tanezumab. Anti-NGF agents have been shown to reduce chronic pain in patients

with osteoarthritis.

Lifestyle Modification, Physical/Occupational Therapy, and Other Nonpharmacologic

Measures

Lifestyle modification, particularly exercise and weight reduction, is a core component in the

management of osteoarthritis.[82, 83] Guidelines from Osteoarthritis Research Society International

(OARSI) advise that nonpharmacologic treatment of hip and knee osteoarthritis should initially

focus on self-help and patient-driven modalities rather than on modalities delivered by health

professionals.[62]

The ACR strongly recommends the following nonpharmacologic measures for patients with knee

or hip osteoarthritis[84] :

Cardiovascular or resistance land-based exercise

Aquatic exercise

Weight loss, for overweight patients

The ACR conditionally recommends the following measures for patients with knee or hip

osteoarthritis:

Self-management programs

Manual therapy in combination with supervised exercise

Psychosocial interventions

Thermal agents

Walking aids, as needed

For patients with knee osteoarthritis, the ACR also conditionally recommends the following

measures:

Medially directed patellar taping

Medially wedged insoles for lateral-compartment osteoarthritis

Laterally wedged subtalar strapped insoles for medial-compartment osteoarthritis

Tai chi

For knee osteoarthritis, an American Academy of Orthopaedic Surgeons (AAOS) guideline

suggests encouraging patients to participate in self-management educational programs such as

those conducted by the Arthritis Foundation and to incorporate activity modifications into their

lifestyle (eg, walking instead of running or engaging in alternative activities).

Instruct the patient to avoid aggravating stress to the affected joint. Implement corrective

procedures if the patient has poor posture.

Weight reduction relieves stress on the affected knees or hips. The benefits of weight loss,

whether obtained through regular exercise and diet or through surgical intervention, may extend

not only to symptom relief but also to a slowing in cartilage loss in weight-bearing joints (eg,

knees).[85] In addition, weight loss lowers levels of the inflammatory cytokines and adipokines

that may play a role in cartilage degradation.[86]

Some patients with osteoarthritis benefit from heat placed locally over the affected joint. A

minority of patients report relief with ice.[87]

Physical activity

Although people with osteoarthritis tend to avoid activity, exercise is an effective treatment for

this condition, producing improvements in pain, physical function, and walking distance. Long-

term walking and resistance-training programs have been shown to slow the functional decline

seen in many patients with osteoarthritis, including older patients.[86]

Osteoarthritis of the knee may result in disuse atrophy of the quadriceps. Because these muscles

help protect the articular cartilage from further stress, quadriceps strengthening is likely to

benefit patients with knee osteoarthritis. Stretching exercises are also important in the treatment

of osteoarthritis because they increase range of motion.

In a study of patients with knee osteoarthritis, Jan et al found that in most respects, non–weight-

bearing exercise was as therapeutically effective as weight-bearing exercise.[88] After an 8-week

exercise program, the 2 types of exercise resulted in equally significant improvements in

function, walking speed, and muscle torque. However, patients in the weight-bearing group

demonstrated greater improvement in position sense, which may help patients with complex

walking tasks, such as walking on a spongy surface.

Chaipinyo and Karoonsupcharoen found no significant difference between home-based strength

training and home-based balance training for knee pain caused by osteoarthritis. However,

greater improvement in knee-related quality of life was noted in the strength-training group.[89]

The importance of aerobic conditioning, particularly low-impact exercises (if osteoarthritis is

affecting weight-bearing joints), should be stressed as well. Swimming, especially the aerobic

aquatic programs developed by the Arthritis Foundation, can be helpful.

The benefits of exercise have been found to decline over time, possibly because of poor

adherence. Factors that determine adherence to exercise have not been carefully studied in

patients with osteoarthritis. In a review of this topic, Marks and Allegrante concluded that

interventions to enhance self-efficacy, social support, and skills in the long-term monitoring of

progress are necessary to foster exercise adherence in people with osteoarthritis.[90]

Tai chi

A prospective, single-blind, randomized, controlled study by Wang et al suggested that tai chi is

a potentially effective treatment for pain associated with osteoarthritis of the knee.[91] In this trial,

40 patients with symptomatic tibiofemoral osteoarthritis who performed 60 minutes of tai chi

twice weekly for 12 weeks experienced significantly greater pain reduction than did control

subjects who underwent 12 weeks of wellness education and stretching.

The mean difference in Western Ontario and McMaster Universities Osteoarthritis Index

(WOMAC) pain scores was −118.80 mm.[91] The tai chi cohort also had significantly better

WOMAC physical function scores, patient and physician global visual analog scale scores, chair

stand times, Center for Epidemiologic Studies Depression Scale scores, self-efficacy scores, and

Short Form 36 physical component summaries.

Similarly, a systematic review and meta-analysis concluded that research results are encouraging

and suggest that tai chi may be effective in controlling pain and improving physical function in

patients with knee osteoarthritis.[92] The researchers noted, however, that the strength of the

evidence is limited by the small number of randomized, controlled trials with a low risk of bias.

Assistive devices

The use of assistive devices for ambulation and for activities of daily living (ADLs) may be

indicated for patients with osteoarthritis. Braces and appropriate footwear may also be of some

use. A cane can be used in the contralateral hand for hip or knee osteoarthritis. The patient can be

taught joint-protection and energy-conservation techniques.

For patients with hand osteoarthritis, the ACR conditionally recommends evaluating the patient’s

ability to perform ADLs and providing assistive devices as needed. The ACR conditionally

recommends splints for patients with trapeziometacarpal joint involvement.[84]

Occupational therapy and physical therapy

Occupational adjustments may be necessary for some patients with osteoarthritis. An

occupational therapist can assist with evaluating how well the patient performs ADLs, as well as

with retraining of the patient as necessary. Joint-protection techniques should be emphasized.

Physical therapy modalities, especially those aimed at deconditioned patients, can be helpful,

particularly in patients with hip or knee involvement.

Electromagnetic field stimulation and TENS

A pulsed electromagnetic field stimulation device (Bionicare) has been approved by the US Food

and Drug Administration (FDA) for use in patients with knee osteoarthritis. Pulsed

electromagnetic field stimulation is believed to act at the level of articular cartilage by

maintaining the proteoglycan composition of chondrocytes through downregulation of its

turnover.[93]

A multicenter, double-blind, randomized, placebo-controlled 4-week trial in 78 patients with

knee osteoarthritis found improved pain and function in those who were treated with the device.[94] A double-blind, placebo-controlled 3-month trial in 58 patients with moderate-to-severe knee

osteoarthritis showed that the use of a highly optimized, capacitively coupled, pulsed electrical

stimulus device yielded significant symptomatic and functional improvement.[95]

Another randomized clinical trial demonstrated that pulsed short-wave treatment was effective in

relieving pain and improving function and quality of life in women with knee osteoarthritis on a

short-term basis; additional studies are needed to validate the 12-month follow-up.[96]

Transcutaneous electrical nerve stimulation (TENS) may be another treatment option for pain

relief. To date, however, there is only limited evidence that TENS is beneficial in this setting. A

systematic review could not confirm that TENS is effective for pain relief in knee osteoarthritis.[97] A randomized controlled trial found that TENS applied in conjunction with therapeutic

exercise and daily activities increased quadriceps activation and function in patients with

tibiofemoral osteoarthritis.[98]

Acupuncture

Acupuncture is becoming a more frequently used option for treatment of the pain and physical

dysfunction associated with osteoarthritis. Some evidence supports its use. For example, a

review article of randomized, controlled trials reported that the level of pain persisting after

acupuncture was significantly lower than the level of pain persisting after control treatments.[99]

Several groups have issued guidelines regarding acupuncture for knee osteoarthritis. The AAOS

neither recommends nor opposes the use of acupuncture for pain relief in knee osteoarthritis,

citing inconclusive evidence.[100]OARSI suggests that acupuncture may yield symptomatic

benefit in these patients.[62] The ACR recommends traditional Chinese acupuncture for patients

with chronic moderate-to-severe pain who would be candidates for total knee arthroplasty but

who either do not want it or have contraindications to it.[84]

Arthroscopy

A procedure of low invasiveness and morbidity, arthroscopy will not interfere with future

surgery. However, a randomized, controlled trial in patients with moderate-to-severe

osteoarthritis found that arthroscopic surgery for osteoarthritis of the knee provided no additional

benefit beyond that afforded by optimized physical and medical therapy.[1]

Arthroscopy is indicated for removal of meniscal tears and loose bodies; less predictable

arthroscopic procedures include debridement of loose articular cartilage with a microfracture

technique and cartilaginous implants in areas of eburnated subchondral bone (see the images

below). These treatments have varying success rates and should be performed only by surgeons

experienced in arthroscopic surgical techniques.[1, 101, 102] Overall, arthroscopy is not recommended

for nonspecific “cleaning of the knee” in osteoarthritis.

Arthroscopic view of a torn meniscus before (top) and after (bottom) removal of loose meniscal

fragments.Arthroscopic view of an arthritic knee.Arthroscopic view of a knee after the removal

of loose fragments of articular and meniscal cartilage.Arthroscopic view of the removal of

cartilaginous loose body.

Patients who undergo arthroscopy usually require a period of crutch use or exercise therapy. This

period typically lasts days but sometimes extends for weeks.

Osteotomy

Osteotomy is used in active patients younger than 60 years who have a malaligned hip or knee

joint and want to continue with reasonable physical activity.[103] The principle underlying this

procedure is to shift weight from the damaged cartilage on the medial aspect of the knee to the

healthy lateral aspect of the knee. Osteotomy is most beneficial for significant genu varum, or

bowleg deformity. (The effectiveness of osteotomy for genu valgum is not highly predictable.)

Osteotomy often can help individuals avoid requiring a total knee replacement until they are

older. It can lessen pain, but it can also lead to more challenging surgery if the patient later

requires arthroplasty.

Contraindications for osteotomy are as follows:

Knee flexion of less than 90°

A flexion-extension contracture of more than 15°

Varus over 15°-20°

Instability from previous trauma or surgery

Severe arterial insufficiency

Bicompartmental involvement

Patients undergoing osteotomy require partial weight-bearing until bony healing occurs.

Afterward, exercise is indicated.

Arthroplasty

Arthroplasty consists of the surgical removal of joint surface and the insertion of a metal and

plastic prosthesis (see the images below). The prosthesis is held in place by cement or by bone

ingrowth into a porous coating on the prosthesis. The use of cement results in faster pain relief,

but bone ingrowth may provide a more durable bond; accordingly, prostheses with a porous

coating are used in younger patients.

Anteroposterior radiograph shows knee replacement in 1 knee

and arthritis in the other, with medial joint-space narrowing and subchondral sclerosis.

Anteroposterior radiograph of the pelvis and hips shows an

arthritic hip not treated surgically and a total hip replacement.

Anteroposterior radiograph obtained after knee replacement. Lateral

radiograph obtained after knee replacement (same patient as in the above image).

Arthroplasty is performed if all other modalities are ineffective and osteotomy is not appropriate

or if a patient cannot perform ADLs despite maximal therapy.[104, 105]This procedure alleviates

pain and may improve function. At a minimum, 10-15 years of viability are expected from joint

replacement in the absence of complications.

Infection is a particular postoperative concern in cases of total joint replacement. This

complication is now rare, however, especially with the use of perioperative antibiotics.

Prevention of thrombophlebitis and resultant pulmonary embolism is important in patients who

undergo lower-extremity arthroplasty procedures for osteoarthritis. The surgeon must use all

means available to prevent these complications. Early motion and ambulation, when possible, are

of particular importance. The use of low-molecular-weight heparin or warfarin is also indicated.

After joint replacement, patients require partial weight-bearing, which progresses to full weight-

bearing in 1-3 months; range-of-motion and strengthening exercises are started within a few days

after joint-replacement surgery and continued until the patient has good range of motion and

strength. After resection arthroplasty of the hip, patients require instruction in the use of crutches

or a walker, which are usually needed permanently.

For more information, see the following articles:

Total Knee Arthroplasty

Unicompartmental Knee Arthroplasty

Surgical Treatment of Interphalangeal Joint Arthritis

Minimally Invasive Total Hip Arthroplasty

Fusion and Joint Lavage

Fusion consists of the union of bones on either side of the joint. This procedure relieves pain but

prevents motion and puts more stress on surrounding joints. Fusion is sometimes used after knee

replacements fail or as a primary procedure for ankle or foot arthritis.

Observational studies suggested a benefit for joint lavage. However, sham-controlled trials

yielded conflicting results, and a meta-analysis concluded that joint lavage does not result in pain

relief or improvement of function in patients with knee osteoarthritis.[106]

Prevention

Overweight patients who have early signs of osteoarthritis or who are at high risk should be

encouraged to lose weight. Recommend quadriceps-strengthening exercises in patients with

osteoarthritis of the knees, except in those with pronounced valgus or varus deformity at the

knees. (See Lifestyle Modification, Physical/Occupational Therapy, and Other

Nonpharmacologic Measures.)

It has been proposed that low vitamin D levels may play a role in the development and

progression of osteoarthritis; however, studies of vitamin D status and osteoarthritis have

produced conflicting results.[107, 108]

A systematic review found no convincing evidence that selenium, vitamin A, or vitamin C is

effective for the treatment of osteoarthritis.[109] A prospective cohort study also found no evidence

that vitamin C supplementation slowed the progression of knee osteoarthritis; however, it did

find that patients who reported taking vitamin C were 11% less likely to develop knee

osteoarthritis.

Berdasarkan pemeriksaan radiologi, Kellgren & Lawrence menyusun gradasi OA lutut

menjadi : 8

·         Grade 0 :  tidak ada OA

·         Grade 1 :  sendi dalam batas normal dengan osteofit meragukan

·         Grade 2 :  terdapat osteofit yang jelas tetapi tepi celah sendi baik dan tak nampak deformitas

tulang.

·         Grade 3 :  terdapat osteofit dan deformitas ujung tulang dan penyempitan celah sendi.

·         Grade 4 :  terdapat osteofit dan deformitas ujung tulang dan disertai hilangnya celah sendi.

TERAPI LATIHAN PADA PENDERITA OA LUTUT

            Latihan merupakan bagian penting dalam manajemen pasien dengan OA lutut. Menurut

Minor, tujuan program latihan pada pasien OA adalah:

1.      Mengurangi  impairmen dan memperbaiki fungsi. Misalnya mengurangi nyeri sendi,

meningkatkan kekuatan otot, meningkatkan luas gerak sendi, menormalkan pola jalan, dan

memperbaiki kemampuan melakukan aktivitas sehari-hari.

2.      Melindungi sendi dari kerusakan lebih lanjut dengan cara mengurangi stress pada sendi,

mengurangi joint forces, dan memperbaiki biomekanik sendi.

3.      Mencegah disabilitas dan menurunnya kesehatan yang terjadi sekunder karena inaktivitas

dengan meningkatkan level aktifitas fisik  sehari-hari dan memperbaiki daya tahan fisik.4

Program latihan pada pasien OA harus disusun secara individual sesuai keadaan pasien.

Pada pasien dengan kelemahan otot yang signifikan dan berkurangnya gerakan sendi, tujuan

awal dari latihan adalah mengurangi impairmen, memperbaiki fungsi, dan persiapan untuk

aktivitas fisik.Pada pasien OA dengan kekuatan otot dan luas gerak sendi (LGS) yang baik maka

program latihan difokuskan pada perlindungan sendi dan general conditioning. 4

Ada beberapa hal yang harus dipertimbangkan dalam menyusun program latihan untuk

penderita OA lutut, yaitu :4,5

1. Derajat penyakit dan alignment sendi

Derajat OA bisa mempengaruhi respon penderitanya terhadap latihan. Penelitian Fransen

dkk menunjukkan bahwa pasien dengan celah sendi lutut sisi medial yang lebih sempit berespon

kurang baik dibandingkan dengan pasien yang celah sendinya lebih lebar. Pada pasien OA

dengan genu varus maka akan terjadi peningkatan beban di sisi medial lutut saat jalan cepat.

Oleh karena itu perlu dgunakan ortosis misalnya dengan lateral wedge, atau knee brace.5 Selain

itu pada kondisi inflamasi akut atau udema sendi yang signifikan, latihan harus ditunda sampai

inflamasi berkurang.4,5

2. Nyeri

Nyeri merupakan gejala utama pada pasien OA yang sering menyebabkan pasien

membatasi aktivitasnya. Latihan penguatan dapat mengurangi keluhan nyeri pada pasien OA.

Pada tahap awal digunakan latihan penguatan otot isometrik karena gerak sendi yang terbatas

sehingga tidak menimbulkan nyeri.4 Selain itu sebelum melakukan latihan aerobik harus

dilakukan latihan pemanasan muskuloskletal dan kardiovaskular serta latihan fleksibilitas.

Latihan dilakukan sebatas gerakan bebas nyeri serta harus menghindari postur dan gerakan

yang  meningkatkan nyeri dan menibulkan udema. Pasien juga diajari untuk memonitor sendiri

latihannya untuk menghindari nyeri dan delayed onset muscle soreness.4,5

3. Usia

            Usia bukan merupakan kontraindikasi melakukan latihan. Guideline latihan sama bisa

diterapkan pada penderita usia lanjut dengan memperhatikan adanya resiko fraktur dan ganguan

keseimbangan. 5

4. Obesitas

            Obesitas merupakan faktor resiko terjadinya OA. Menurunkan berat badan diketahui

menurunkan gejala OA dan resiko terjadinya OA. Program penurunan berat badan harus

termasuk dalam program latihan pasien OA dengan obesitas. Berjalan dengan kecepatan sedang,

bersepeda, dan latihan di air merupakan latihan yang aman dan bermanfaat untuk pasien OA

lutut dan hip, termasuk pasien yang obesitas/overweight.5

3.1. Latihan untuk pasien OA lutut

            Belum ada formula latihan yang pasti untuk pasien OA lutut. Walaupun demikian prinsip

yang umum digunakan dalam program rehabilitasi medik untuk pasien OA terdiri dari beberapa

komponen seperti pada tabel berikut. 7

                      

3.1.1. Latihan luas gerak sendi (LGS)/fleksibilitas dan peregangan/stretching

            Pada saat gerakan sendi terjadi kompresi dan dekompresi kartilago sendi yang penting

untuk nutrisi adekuat dan keseimbangan aktivitas anabolik dan katabolik di kartilago sendi.

Imobilisasi dan joint loading yang tidak adekuat menyebabkan atrophy kartilago. Inaktivitas juga

menyebabkan berkurangnya fleksibilitas dan berkurangnya compliance kapsul sendi, ligamen,

dan sinovium.5

Prinsip umum latihan LGS adalah bahwa sendi terutama sendi lutut digerakkan pada luas

gerak sendi penuh untuk mencegah motion loss yang sering terjadi pada sendi OA. Latihan LGS

aktif diberikan apabila pasien mempunyai LGS penuh dan kekuatan otot yang cukup untuk dapat

menggerakkan ototnya sendiri. Latihan LGS aktif assistif diberikan jika kekuatan otot pasien

tidak cukup kuat untuk dapat menggerakkan sendinya sendiri.7 Latihan LGS dilakukan pada

sendi lutut dan sendi lain yang berdekatan serta sendi-sendi kontralateral.5

Berkurangnya LGS merupakan sekuele yang sering terjadi pada penderita OA. Pada OA

lutut umumnya terjadi berkurangnya ekstensi (lag extension), tetapi fleksi lutut pun sering

berkurang. Ada beberapa faktor yang bisa menyebabkan berkurangnya LGS pada OA, antara lain

perubahan pada sendi, pemendekan struktur myotendinosus di sekitar sendi karena nyeri dan

kelemahan. Otot yang lebih pendek dari panjang idealnya menyebabkan kerugian secara

biomekanik saat ia bekerja. Oleh karena itu latihan peregangan harus diberikan sejak awal.12

Latihan fleksibilitas dimulai dengan pasien menggerakkan sendinya pada seluruh luas

gerak sendi yang ada untuk mencegah berkurangnya luas gerak sendi. Selanjutnya ditambahkan

latihan peregangan yang dilakukan dengan pelan, gentle, dan sustained stretching. Sustained

stretching adalah menahan peregangan selama 20-40 detik, atau lebih, kemudian relaks, dan

mengulangi peregangan lagi. Peregangan yang tiba-tiba, kasar, atau ballistic stretching harus

dihindari karena bisa menimbulkan eksaserbasi OA. Untuk pasien OA hip dan lutut otot yang

penting untuk diregangkan adalah otot quadrisep dan hamstring.12

Luas gerak sendi yang cukup, kekuatan otot, dan daya tahan sangat penting untuk

aktivitas berjalan, keseimbangan, naik-turun tangga, dan bangkit dari kursi. Tabel berikut

menunjukkan LGS ekstremitas bawah yang diperlukan untuk beberapa aktivitas

Tabel 3.2. LGS fungsional untuk ekstremitas bawah4

Sendi Gerakan Luas gerak sendi (o)Berjalan di tempat datar

Naik tangga Bangkit dari kursi

Panggul Ekstensi 15 7 0Fleksi 37 67 112Abduksi 7 8 20Adduksi 5 - -Rotasi interna 4 - -Rotasi eksterna 9 10 17

Lutut Ekstensi 0 0 0Fleksi 70 83 93

Pergelangan kaki

Dorsofleksi 10 15 15Plantarfleksi 15 10 -

Latihan ROM rutin setiap hari dengan periode weight bearing dan non weight

bearingpenting untuk menjaga kesehatan sendi. Pada individu tertentu diperlukan latihan yang

didesain khusus sesuai impaiment dan pathologi sendinya. Umumnya petunjuk untuk latihan

fleksibilitas menurut American College of Sports Medicine (ACSM) dan Centers for Disease

Control and Prevention (CDC)  adalah sebagai berikut.5

3.1.2. Latihan Penguatan

            Kelemahan otot, terutama otot quadrisep, telah diketahui sangat berhubungan dengan OA

lutut. Kelemahan quadrisep pada OA lutut disebabkan oleh inhibisi neuromuskuler yang terjadi

karena nyeri dan efusi, dan disuse atrophy karena inaktivitas. Penelitian menunjukkan bahwa

kelemahan otot quadrisep juga bisa terjadi sebelum OA dan menjadi faktor resiko terjadinya OA

lutut.5  Oleh karena itu penguatan otot quadrisep menjadi fokus dalam latihan penguatan untuk

pasien OA lutut.

            Latihan penguatan bisa dibedakan menjadi isometrik, isotonik, dan isokinetik. Latihan

penguatan isometrik adalah bentuk latihan statik dimana otot berkontraksi dan

menghasilkan forcetanpa perubahan panjang otot dan sedikit/tanpa gerakan sendi. Latihan

isometrik digunakan jika pasien tidak dapat mentoleransi gerakan sendi berulang, misalnya pada

sendi yang nyeri atau inflamasi. Latihan isometrik mudah dipelajari dan bisa meningkatkan

kekuatan otot dengan cepat, tetapi manfaat fungsionalnya terbatas. 12

            Latihan penguatan isotonik adalah latihan penguatan dinamik dengan beban konstan

dimana otot berkontraksi memanjang (eksentrik) atau memendek (konsentrik) di sepanjang luas

gerak sendinya. Kontraksi eksentrik menyebabkan stress yang lebih besar tetapi menghasilkan

kekuatan otot yang lebih besar pula. Latihan isotonik bemanfaat untuk meningkatkan kekuatan

otot, daya tahan, dan power.     Latihan isokinetik adalah latihan dengan gerak terkendali

sehingga gerakan terjadi melalui suatu rentang sendi pada kecepatan angular yang konstan

selama otot memendek atau memanjang dengan beban dapat bervariasi.12,13 Menurut deLisa

latihan ini jarang digunakan karena memerlukan peralatan isokinetik untuk latihan dan

hubungannya dengan aktivitas fungsional masih belum jelas.12 Walaupun demikian, beberapa

penulis mengatakan bahwa latihan isokinetik dapat menguatkan otot lebih efisien dibandingkan

latihan isotonik. 13

            Latihan penguatan juga bisa dibedakan menjadi latihan closed kinetic chain (bagian distal

ekstremitas terfiksasi) dan open kinetic chain (bagian distal ekstremitas bebas). Latihan open

kinetic chain memungkinkan penderita melakukan penguatan secara spesifik pada satu

gerakan/otot pada satu sendi, misalnya penguatan ekstensor lutut, tetapi latihan ini

meningkatkanshear forces pada sendi sehingga bisa menimbulkan eksaserbasi OA

lutut. Quadricep setting, SLR, dan PRE dengan quadriceps bench adalah contoh latihan open

kinetic chain. Latihan closed kinetic chain menyebabkan shear forces yang lebih kecil dan lebih

menyerupai aktivitas sinergis dan firing pattern untuk aktivitas sehari-hari12. Contoh

latihan closed kinetic chain untuk OA lutut antara lain partial/mini squat, wall slides, dan lunge.

Latihan penguatan dimulai dengan latihan penguatan isometrik (brief isometric exercise)

karena latihan ini tidak melibatkan gerakan sendi dan tidak memperberat gejala OA lutut.  Sendi

lutut diposisikan pada posisi yang nyaman (biasanya posisi ekstensi) dan kemudian otot

quadrisep dikontraksikan maksimal selama minimal 6 detik, minimal dilakukan 2 kali

sehari.Sambil melakukan kontraksi otot pasien diminta untuk menghitung dengan suara keras

untuk menghindari manuver Valsava. Penggunaan elastic belt atau rubber loop yang terbuat

dari tire inner tube ( ban dalam) merupakan cara praktis untuk mendapat feedback proprioseptif

saat otot berkontraksi isometrik melawan tahanan.(gambar3.1).14

               

Kontraksi isometrik harus ditahan minimal 6 detik untuk  memungkinkan tercapainya

puncak tegangan otot dan perubahan metabolik di otot, dan tidak boleh lebih dari 10 detik karena

akan menyebabkan otot cepat kelelahan/fatique. 13

Latihan quadricep setting adalah contoh latihan penguatan isometrik otot quadrisep

dengan fokus pada kontraksi vastus medialis obliq. Latihan dilakukan dengan pasien posisi

supine atau duduk dan lutut posisi ekstensi dan pergelangan kaki dorsifleksi. Pasien diberi

perintah ”tekan lutut anda ke bawah, dan kencangkan otot paha”. Kontraksi ditahan selama 10

detik, istirahat beberapa detik, dan kemudian kontraksi lagi.13,15  Latihan dilakukan 8-12 kali

repetisi, diulang beberapa kali sehari. Jika pasien merasa kurang nyaman, bisa ditambahkan

ulungan handuk di bawah lutut.15

Latihan stright leg rising (SLR) adalah latihan penguatan isometrik otot quadrisep

dengan fokus pada otot rectus femoris. Latihan ini juga melibatkan kontraksi dinamik otot

fleksor hip. Posisi pasien supine dengan lutut ekstensi. Untuk menstanbilkan pelvis dan

punggung bawah, hip dan lutut kontra lateral diposisikan fleksi, kaki diletakkan netral di alas

latihan. Pasien diperintahkan untuk mengkontraksikan quadrisep, kemudian tungkai diangkat

sekitar 45o fleksi hip sambil lutut tetap ekstensi. Tungkai ditahan pada posisi tersebut selama 10

hitungan kemudian tungkai diturunkan. Sesuai dengan kemampuan pasien, tungkai bisa

diturunkan 30o atau 15o fleksi hip untuk menambah beban pada quadrisep, atau dengan

menambahkan beban di pergelangan kaki. 13

Untuk menghindari cedera pada otot, berikan tahanan secara bertahap, serta turunan

kontraksi otot secara bertahap pula. Hal ini membantu peningkatan tegangan/tension otot secara

bertahap, menjamin kontraksi otot yang bebas nyeri, dan menghindari resiko gerakan sendi yang

tidak terkontrol. Menahan nafas (valsava manuver) sering terjadi saat penderita melakukan

latihan isometrik. Hal ini harus dihindari karena bisa meningkatkan tekanan darah dengan

cepat. Rhytmic breathing dengan penekanan pada ekspirasi saat melakukan kontraksi otot, harus

dilakukan saat melakukan latihan isometrik untuk mengurangi resiko tersebut. Latihan isometrik

dengan intensitas tinggi merupakan kontra indikasi bagi penderita dengan gangguan jantung dan

vaskuler.13

Progressive resistance exercise (PRE) adalah latihan penguatan isotonik dinamik dengan

beban yang ditingkatkan secara bertahap. Latihan penguatan dengan PRE lebih baik untuk

menjaga dan meningkatkan fungsi otot, mengurangi nyeri sendi, dan meningkatkan fungsi pasien

OA lutut.4,13            Salah satu metode untuk PRE adalah metode DeLorme-Watkins yang terdiri

dari serial kontraksi otot dengan beban meningkat sehingga pada akhir latihan otot mengangkat

beban yang maksimal.13 Latihan ini bisa dilakukan dengan NK table/quadirceps bench. Caranya

adalah sebagai berikut :

a.       Tentukan beban maksimal 10 kali repetisi (10 repetition maximal resistance/ 10 RM), yaitu

beban maksimal yang bisa diangkat oleh otot 10 kali pada  luas gerak sendi penuh .

b.      Pasien kemudian diminta melakukan latihan :

-          10 kali repetisi dengan beban ½ dari 10 RM

-          10 kali repetisi dengan beban ¾ dari 10 RM

-          10 kali repetisi dengan beban 10 RM penuh

c.       pasien beristirahat sebentar ( 5 menit) diantara bout latihan

d.      pada prosedur ini sudah termasuk latihan pemanasan karena awalnya pasien mengangkat beban

hanya ½ dan ¾ RM

e.       nilai 10 RM ditingkatkan setiap minggu sesuai dengan peningkatan kekuatan otot. 13

                  Wall slides adalah salah satu latihan penguatan closed kinetik chain untuk otot

quadrisep. Caranya, penderita berdiri bersandar pada dinding dengan jarak antara kaki dengan

dinding sekitar 1 kaki(32cm), kemudian punggung digeser ke bawah samapi lutut fleksi sekitar

20-30o. Jika ditambahkan kontraksi quadrisep sebelah medial dengan menjepit bola diantara

kedua lutut maka penguatan terutama ditujukan untuk otot vastus medialis. Kontraksi ditahan

selama 10 detik, kemudian penderita menaikkan kembali badannya. Latihan diulang 8-12 kali

dengan istirahat diantara kontraksi. Otot vastus medialis merupakan otot yang paling sering

mengalami kelemahan diantara kelompok otot quadrisep dan bisa menyebabkan gerakan patella

yang tidak normal.15

Latihan penguatan otot sangat penting untuk pasien OA lutut karena otot yang lemah bisa

menambah disfungsi/kerusakan/gangguan pada sendi dan otot yang kuat akan melindungi sendi.

Walaupun demikian harus dihindari latihan penguatan yang menyebabkan bertambanya

kerusakan dan nyeri sendi. Caranya dengan melakukan latihan isometrik pada posisi-posisi yang

bebas nyeri (multiple angle isometric in pain free positions), melakukan latihan beban pada luas

gerak sendi yang tidak nyeri, dan latihan di kolam. Latihan dengan beban pada luas gerak sendi

45-90o fleksi cenderung menimbulkan nyeri patelofemoral karena gaya kompresi pada patella.13

3.1.3. Latihan Aerobik

            Latihan aerobik penting untuk penderita OA lutut karena pada penderita OA lutut sering

terjadi penurunan kapasitas aerobik sebagai akibat kurangnya aktivitas. Manfaat latihan aerobik

antara lain meningkatkan kapasitas aerobik, kekuatan otot, daya tahan, serta pengurangan berat

badan. Selain itu latihan aerobik juga dapat menyebabkan pelepasan opioid endogen, serta

memperbaiki gejala depresi dan kecemasan.4,7

Latihan aerobik bisa dilakukan di darat dan di air (aquaterapi). Bentuk latihan aerobik

yang dianjurkan adalah berjalan, bersepeda, berenang, senam aerobik, dan senam aerobik di

kolam. Berenang dan latihan di kolam menimbulkan stress sendi yang lebih ringan dibandingkan

bentuk latihan aerobik yang lain. Setiap sesion latihan aerobik harus diawali oleh latihan

pemanasan yang terdiri dari latihan ROM dan diikuti oleh pendinginan dan peregangan. 4

Jika latihan jalan kaki atau jogging menyebabkan gejala yang dikeluhkan pasien

bertambah berat, intensitas latihan harus dikurangi atau bentuk latihan dirubah. Alas kaki yang

baik sangat penting dan latihan lebih baik dilakukan di permukaan yang lunak. Untuk dapat

meningkatkan kapasitas aerobik heart rate yang harus dicapai adalah 60-80% dari target heart

rateuntuk latihan selama 20-30 menit, 3-4 kali seminggu. Naik turun tangga juga merupakan

bentuk latihan aerobik yang baik, tapi menyebabkan joint loading yang maksimal pada hip dan

lutut sehingga tidak dianjurkan untuk pasien OA lutut dan hip.4

Latihan dengan sepeda statik dilakukan dengan setting lutut ekstensi saat pedal sepeda

berada di bawah. 13,16 Tingkat beban diatur bertahap mulai dari minimal sampai sedang. Latihan

dilakukan 5 menit dengan beban ringan selama 2 hari, kemudian beban dinaikkan dan waktu

ditambah 5 menit. Setiap peningkatan level dilatih selama 3 hari sampai waktu latihan 20-30

menit.16

 Berikut adalah rekomendasi petunjuk latihan daya tahan kardiovaskular dan

muskuloskletal untuk pasien OA lutut dan hip dengan awal latihan menggunakan intensitas dan

durasi yang paling rendah, kemudian secara bertahap ditingkatkan.5

Tabel 3.4. Petunjuk latihan daya tahan kardiovaskuler dan daya tahan otot5

3.1.4. Latihan Fungsional

            Pasien  OA lutut sering mengalami gangguan aktivitas seperti naik turun tangga, duduk

dan bangkit dari kursi atau toilet, atau mengambil benda dari lantai. Perlu dilakukan latihan yang

bertujuan mengatasi gangguan fungsional khusus yang dialami pasien. Latihan ini berupa latihan

penguatan dengan modifikasi aktivitas sehari-hari. Contohnya adalah sebagai berikut13:

-          Latihan step-up dan step down : latihan naik dan turun tangga.13

-          Wall slides dan mini squat sampai 90o atau  sebatas toleransi: bertujuan melatih aktivitas

duduk dan berdiri dari duduk dengan bantuan lengan, serta menentukan perlu tidaknya

adaptasi  tinggi kursi untuk fungsi yang lebih aman.13

                       

                              

-          Partial lunge : bertujuan melatih mekanika tubuh yang efektif untuk mengambil benda di

lantai dengan konsentrasi pada kontrol otot trunk saat melakukan gerakan. Pasien diajarkan

untuk mengkontraksikan otot abdomen untuk menstabilkan pelvis saat melakukan gerakan

lunge.13

                                 

-          Latihan keseimbangan dan proprioseptif, dimulai bila pasien mempunyai kemampuan kontrol

yang baik, misalnya dengan berjalan sepanjang garis sempit, latihan dengan bola Swiss, atau latihan

keseimbangan dengan wobble board. 13,17 Latihan Tai Chi juga efektif untuk memperbaiki

keseimbangan pada penderita OA.13 Menurut deLisa belum ada metode paling baik untuk

mengoptimalkan keseimbangan pada penderita OA, tetapi beberapa penelitian menunjukkan bahwa

latihan penguatan dan latihan aerobik dengan berjalan memperbaiki stabilitas postural penderita

OA 12

             

                      Gambar 3.9. Latihan dengan bola Swiss17

-          Latihan ambulasi : penggunaan alat bantu jalan dikurangi ketika kekutan otot quadrisep

membaik ( MMT 4/5) atau nyeri berkurang. Latihan ambulasi dilakukan pada permukaan yang

bervariasi, naik turun ramp, pertama dengan bantuan kemudian mandiri.13

3.2. Edukasi dan Home Exercise Program

Edukasi dan program latihan di rumah merupakan hal yang penting bagi penderita OA.

Edukasi yang diberikan terutama tentang penyakit OA, prinsip perlidungan sendi, bagaimana

manajemen gejala OA, dan program latihan di rumah. Program yang diberikan adalah latihan

yang aman dilakukan di rumah berupa latihan penguatan otot, latihan luas gerak sendi, dan

latihan enduran/daya tahan. Pasien dengan berat badan lebih dianjurkan untuk mengurangi berat

badannya. 13

Proteksi dan pemeliharaan sendi lutut antara lain dengan  menghindari gerakan fleksi

yang berlebihan, menghindari memposisikan sendi pada satu posisi dalam waktu yang lama,

menghindari overuse, mengontrol berat badan, mengurangi beban pada sendi yang nyeri,

menyeimbangkan  aktivitas dan istirahat, mendistribusikan tekanan, menggunakan otot dan sendi

yang paling kuat, dan menggunakan gerakan dengan biomekanik yang baik. 7,11

Home exercise program atau program latihan di rumah sangat penting bagi pasien OA

lutut. Kepatuhan jangka panjang untuk melakukan latihan di rumah merupakan tujuan yang

utama karena sangat berhubungan dengan perbaikan fungsi fisik penderita OA. 8  Berikut contoh

leaflet latihan di rumah untuk pasien OA.

Gambar 3.6. Latihan untuk OA10